Most persons diagnosed with cancer do not report a single symptom;instead they have multiple symptoms associated with the disease and treatment. The interactive and cumulative effect of multiple symptoms adversely affects quality of life. Three or more symptoms which occur concurrently are called a symptom cluster. The most common cancer diagnosed in men is prostate cancer and yet there is a paucity of information on the prostate cancer symptom experience. Even more limiting are findings on symptom clusters in men with prostate cancer who often experience general symptoms of fatigue, pain, insomnia, depression, and anxiety and specific treatment related symptoms. Cytokines are viewed as potential biomarkers for symptoms and symptom clusters as they may contribute to the occurrence of multiple cancer-related symptoms. The specific aims in this exploratory study are to 1) identify symptom clusters, 2) examine the relationship of patient factors (e.g., age, cancer stage, comorbidities) and symptom clusters, 3) evaluate the effect of symptom clusters on quality of life, and 4) explore relationships of cytokine levels with symptom clusters in men undergoing primary radiation treatment for stage I, II or III prostate cancer. Men (n=95) who are about to undergo treatment will be recruited from four outpatient radiation treatment facilities. Participants will be assessed for general and specific treatment related symptoms at baseline and after 8 weeks of treatment. A subsample of 36 men will be randomly selected for blood draws to assess cytokine levels over time in relation to the symptom clusters. Latent class analysis will be used to identify subgroups of men with different symptom experiences. MANOVA and chi-square tests will be used to examine if patient factors differentiate the cluster groups. Mixed effects linear models will be used to assess the relationship between symptom clusters, quality of life, and biomarkers. Findings from this study will provide the basis for the development of a tailored intervention for men with prostate cancer that would target the management of multiple symptoms while improving QOL. Lessening the symptom burden through intervention strategies that unravel the cluster is imperative in making the cancer experience more manageable. PUBLIC HEALTH RELEVANCE: This project focuses on the symptoms of men receiving radiation treatment for prostate cancer. Symptoms will be examined to determine if they cluster and symptom clusters will be evaluated for their impact on quality of life. Blood samples will be drawn from participants to explore if inflammatory markers in the blood are related to symptom clusters.